﻿using System.Collections.Generic;
using System;
using Semisugar.EventBus;
using System.IO;
using Unity.IO.Compression;

public class SharedBuffer : AbstractSmartObj
{
    public byte[] buffer = new byte[Utility.kSharedBufferSize];
    public SharedBuffer() { }
    public override void OnRelease() { }
}

public static class Utility
{
    public static class CRC32
    {
        private static uint[] crc32_table =
        {
            0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419,
            0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4,
            0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07,
            0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE,
            0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856,
            0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
            0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4,
            0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,
            0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3,
            0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A,
            0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599,
            0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
            0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190,
            0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F,
            0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E,
            0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,
            0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED,
            0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
            0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3,
            0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2,
            0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A,
            0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5,
            0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010,
            0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
            0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17,
            0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6,
            0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615,
            0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8,
            0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344,
            0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
            0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A,
            0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,
            0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1,
            0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C,
            0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF,
            0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
            0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE,
            0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31,
            0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C,
            0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,
            0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B,
            0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
            0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1,
            0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
            0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278,
            0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7,
            0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66,
            0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
            0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605,
            0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8,
            0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B,
            0x2D02EF8D
        };

        public static uint Crc32(byte[] data, int length)
        {
            uint crc = 0xffffffff;
            for (int ii = 0; ii < length; ++ii)
            {
                crc = ((crc >> 8) & 0x00ffffff) ^ crc32_table[(crc ^ data[ii]) & 0xff];
            }
            crc ^= 0xffffffff;
            return crc;
        }

        public static uint Crc32(byte[] data)
        {
            return Crc32(data, data.Length);
        }
    }

    public const int kSharedBufferSize = 4096;

    public delegate int InsertComparsionFunc<T>(T atom, T curr, T last);
    public static bool LinkedListInsert<T>(LinkedList<T> list, T atom, InsertComparsionFunc<T> func)
    {
        if (list != null && atom != null)
        {
            if (list.Count == 0)
            {
                list.AddFirst(atom);
                return true;
            }

            LinkedListNode<T> node = list.First, nodePrev = default(LinkedListNode<T>);
            while (node != null && node.Value != null)
            {
                T curr = node.Value;
                T last = nodePrev != null ? nodePrev.Value : default(T);
                int result = func(atom, curr, last);
                if (result == -1)
                {
                    list.AddBefore(node, atom);
                    return true;
                }
                else if (result == 1)
                {
                    list.AddAfter(nodePrev, atom);
                    return true;
                }
                else if (result == 2) // the atom has already in the list
                {
                    return false;
                }
                nodePrev = node;
                node = node.Next;
            }

            if (func(atom, nodePrev.Value, default(T)) != 2)
            {
                // add tail
                list.AddLast(atom);
                return true;
            }
        }

        return false;
    }

    // Kaede Tips
    // @indata: uncompressed data
    // @size: the length of indata
    // @outdata: compressed data
    // return: used size of outdata
    // NOTICE: the function will not check the length of outdata.
    public static int SparseArray_Compress(byte[] indata, int size, ref byte[] outdata)
    {
        int j = 1;
        byte padding = (byte)(size % 8);
        //outdata[j++] = padding;
        //outdata[j++] = 0; // position of last tag

        for (int ii = 0; ii < size;)
        {
            byte tag = 0;
            int tagId = j++;
            int limit = Math.Min(8, size - ii);
            for (int jj = 0; jj < limit; ++jj)
            {
                if (indata[ii + jj] != 0)
                {
                    tag |= (byte)(1 << jj);
                    outdata[j++] = indata[ii + jj];
                }
            }

            outdata[tagId] = tag;
            ii += limit;
            if (ii >= size)
                outdata[0] = (byte)((padding << 4) | (byte)(j - tagId));
        }

        return j;
    }

    // Kaede Tips
    // @indata: compressed data
    // @size: the length of indata
    // @outdata: decompressed data
    // return: used size of outdata
    // NOTICE: the function will not check the length of outdata.
    public static int SparseArray_Decompress(byte[] indata, int size, ref byte[] outdata)
    {
        int pos = 0;
        byte padding = (byte)((indata[0] & 0xf0) >> 4);
        byte maskpos = (byte)(indata[0] & 0x0f);
        int limit = 8;
        for (int ii = 1; ii < size;)
        {
            byte tag = indata[ii++];
            for (int jj = 0; jj < limit; ++jj)
            {
                byte mask = (byte)(((1 << jj) & tag) >> jj);
                if (mask == 1)
                    outdata[pos++] = indata[ii++];
                else
                    outdata[pos++] = 0;
            }

            if (ii == size - maskpos)
                limit = padding > 0 ? (int)padding : 8;
        }

        return pos;
    }

    public static int NextPowerOfTwo(int n)
    {
        int s = 1;
        while (s < n)
            s *= 2;

        return s;
    }

    public static void NotifyEvents(object sender, int channel, int op)
    {
        MEObjDeliver e = SmartReferencePool.instance.Fetch<MEObjDeliver>();
        e.opcode = op;
        Mercury.instance.Broadcast(channel, sender, e);
    }

    public static int Gzip_DecompressData(byte[] indata, out byte[] outdata)
    {
        int length = 0;
        using (Stream input = new MemoryStream(indata))
        {
            Stream decompressor = new GZipStream(input, CompressionMode.Decompress);
            length = Zlib_Internal_DecompressBuffer(decompressor, out outdata);
        }
        return length;
    }

    public static int Gzip_CompressData(byte[] indata, out byte[] outdata)
    {
        SharedBuffer sb = SmartReferencePool.instance.Fetch<SharedBuffer>();
        int size = indata.Length * 4 + 512; // include header of gzip and footview info
        if (sb.buffer.Length < size)
            sb.buffer = new byte[Utility.NextPowerOfTwo(size)];

        int length = 0;
        Stream input = null;
        outdata = null;

        input = new MemoryStream(sb.buffer, 0, sb.buffer.Length, true, true);
        Stream compressor = new GZipStream(input, CompressionMode.Compress, true);
        length = Zlib_Internal_CompressBuffer(indata, indata.Length, compressor, out outdata);

        input.Close();
        sb.Release();
        return length;
    }

    private static int Zlib_Internal_CompressBuffer(byte[] rawdata, int rawdataLength, Stream compressor, out byte[] outdata)
    {
        outdata = null;
        if (rawdata == null || rawdataLength <= 0 || rawdata.Length < rawdataLength)
            return 0;

        int length = 0;
        bool hasException = false;
        GZipStream gzip = (GZipStream)compressor;
        MemoryStream ms = (MemoryStream)gzip.BaseStream;

        try
        {
            compressor.Write(rawdata, 0, rawdataLength);
            compressor.Close();
        }
        catch (Exception e)
        {
            hasException = true;
            UnityEngine.Debug.LogError("FAILURE: Zlib_Internal_CompressBuffer - data length = " + rawdataLength + ", " + e.Message);
        }

        if (hasException)
        {
            length = 0;
        }
        else
        {
            length = (int)ms.Position;
            SharedBuffer sb = SmartReferencePool.instance.Fetch<SharedBuffer>();
            if (sb.buffer.Length < length)
                sb.buffer = new byte[Utility.NextPowerOfTwo(length)];

            outdata = sb.buffer;
            Buffer.BlockCopy(ms.GetBuffer(), 0, outdata, 0, length);

            sb.Release();
        }

        return length;
    }

    private static int Zlib_Internal_DecompressBuffer(Stream decompressor, out byte[] outdata)
    {
        SharedBuffer sb = SmartReferencePool.instance.Fetch<SharedBuffer>();
        SharedBuffer outputBuffer = SmartReferencePool.instance.Fetch<SharedBuffer>();

        byte[] working = sb.buffer;
        int length = 0, pos = 0;
        using (decompressor)
        {
            int n;
            while ((n = decompressor.Read(working, 0, working.Length)) != 0)
            {
                length += n;

                if (pos + n >= outputBuffer.buffer.Length)
                {
                    // grow
                    byte[] swapBuffer = new byte[Utility.NextPowerOfTwo(outputBuffer.buffer.Length + n)];
                    Buffer.BlockCopy(outputBuffer.buffer, 0, swapBuffer, 0, pos);
                    outputBuffer.buffer = swapBuffer;
                }

                Buffer.BlockCopy(working, 0, outputBuffer.buffer, pos, n);
                pos += n;
            }
        }
        outdata = outputBuffer.buffer;
        sb.Release();
        outputBuffer.Release();

        return length;
    }
}